CVE-2016-2848 in BIND
Summary
by MITRE
ISC BIND 9.1.0 through 9.8.4-P2 and 9.9.0 through 9.9.2-P2 allows remote attackers to cause a denial of service (assertion failure and daemon exit) via malformed options data in an OPT resource record.
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Analysis
by VulDB Data Team • 09/28/2022
The vulnerability identified as CVE-2016-2848 affects the Internet Systems Consortium BIND DNS server software across multiple version ranges including 9.1.0 through 9.8.4-P2 and 9.9.0 through 9.9.2-P2. This represents a critical denial of service flaw that can be exploited remotely by attackers to crash the DNS daemon through specifically crafted malformed data within OPT resource records. The issue stems from insufficient input validation mechanisms within the DNS server's handling of optional record data, creating a condition where malformed options data triggers an assertion failure that causes the daemon to terminate unexpectedly.
The technical flaw manifests when the BIND server processes OPT resource records containing malformed options data that violates expected data structures or validation rules. This vulnerability specifically targets the assertion mechanism within the DNS server's processing pipeline, where an assertion failure occurs during the parsing of malformed OPT records. The assertion failure represents a fundamental programming error where the software encounters an unexpected condition that violates internal assumptions about data integrity. According to CWE-248, this vulnerability maps to an unrecovered exception condition where the program fails to handle malformed input gracefully, leading to a crash state. The daemon's termination creates a complete denial of service condition that prevents legitimate DNS queries from being processed.
The operational impact of CVE-2016-2848 extends beyond simple service disruption to potentially compromise network infrastructure stability and availability. When exploited, this vulnerability allows remote attackers to cause cascading failures in DNS resolution services that may affect downstream systems relying on proper DNS functionality. The vulnerability is particularly dangerous because it can be triggered without authentication requirements, making it accessible to any remote attacker with network connectivity to the affected DNS server. The attack vector involves sending specially crafted DNS queries containing malformed OPT records that, when processed by the vulnerable BIND version, cause the daemon to exit and restart, potentially creating a denial of service condition that can persist until manual intervention occurs.
This vulnerability aligns with ATT&CK technique T1499.004 which covers network denial of service attacks through exploitation of software vulnerabilities. The impact of such attacks can be significant for organizations relying on DNS infrastructure, as DNS service disruption can affect email delivery, web browsing, and other network-dependent services. Organizations using affected BIND versions should implement immediate mitigation strategies including patching to the latest stable releases, implementing network-level filtering to block malformed DNS traffic, and configuring intrusion detection systems to monitor for exploitation attempts. The vulnerability demonstrates the importance of proper input validation and error handling in network services, as highlighted by CWE-707 which addresses improper handling of security-relevant inputs. Additionally, the issue underscores the need for comprehensive testing of DNS server configurations and regular security assessments to identify similar vulnerabilities in critical infrastructure components.
Organizations should prioritize patching affected systems as the primary mitigation strategy, with the affected versions being updated to BIND 9.8.4-P3 or 9.9.2-P3 which contain the necessary fixes for this assertion failure condition. Network administrators should also consider implementing rate limiting and traffic filtering mechanisms to reduce the impact of potential exploitation attempts while patches are being deployed. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date DNS server software and implementing robust security monitoring practices to detect and respond to exploitation attempts against core infrastructure components.